The date of the Sawan first Pradosh Vrat.
A well-known Hindu festival called Pradosh vrat or Pradosham is devoted to Lord Shiva and Goddess Parvati. On the Trayodashi tithi (13th day) of both Krishna Paksha and Shukla Paksha, pradosh vrat is observed. Thus, it occurs twice each month according to the Hindu calendar. In Hindi, the word "pradosh" means "the first part of the night" or "belonging to or relating to the evening." This holy fast is known as the Pradosh vrat because it is kept during the 'Sandhyakaal,' or evening twilight. On this day, devotees in some regions of India worship Lord Shiva in his Nataraj form.